Carbon paper and method of making same



July 21, 1925. V 1,546,747

W. P. PEMBROKE CARBON PAPER AND METHOD 0F MAKING SAME Filed Aug. 4, 1922Fax @nlazlnitg t fgsollule lblorloawz v m 27 1 fm 1/ with filecINVENTORI Fthfieldflfifrvblbke.

421;, ATTORNEYS.

Patented July 21, 192! UNITED STATES PATENT OFFICE.

WINFIELD P. PEMBROKE, OF ROCHESTER, NEW YORK,

ASSIGNOR TO LOX MANIT- FACTUBING COMPANY, OF ROCHESTER, NEW YORK, ACORPORATION OF NEW.

YORK.

cannon-rerun Ann munch on maxim samn.

Application filed August 4, 1922. SeriaLRo. 579,752.-

To all whom it may concern:

Be it known that I, WINFIELD P. PEM

nnonn, a citizen of the United States, and

resident of Rochester, in the county of Monroe and State of New York,have invented.

. classes, namely, those which produce a substantially non-permanentrecord and are employed. for pencil carbons and those which produce asubstantially permanent record and are employed most generally formaking copies on typewriting machines.

Those-carbon sheets of the first class employ a highsaturable carrier orpaper with in a heated condition for an extremely penetrating color orcoating, due to the use of little or no insoluble coloring matters inthe coating and to the use ofbut a small amount of wax. The other classof carbon sheets employsa high grade of paper stock mostgenerally linentissue as a carrier, and a color-coating high in wax-content and lowinsoluble color content.

In manufacturing the second class of carbon sheets,'it is customary toemploy a coat ing containing a wax with an insoluble color, suchf forinstance, as lamp black. This is ap liedto one 'face of the carrierwhile in a of. condition, and after properly being spread over thecarrier, is immediately subjected to a cooling action for the reasonthat if the wax in the coating is maintained too long a period of time,the most (1 sirable carbon paper is not obtained. Owigrg to the shortperiod of time that-the col coating is'heated, the color coating doesnot have sufiicient time to penetrate the carrier, so that the carbonsheet produced has the color coating adhering substantially only to .theface thereon. Such acarbon sheet has two disadvantages; first, the sheetis substantially a'stencil and upon each use thereof a great, deal ofthe coating comes ofi, so that the life of the carbon sheet iscomparativel limited; and second, the coating has a di erent coeflicientof expansion from that of the carthe stored goods.

the application of the. two coatings, the

from the pulp after the cha over machines now possible to arrange thesheet in a flat condi tion and interfering With the handling of thesheets in use; The life of such carbon sheets may be slightly increasedby ageing them, that is, permitting them to stand for .a considerablelength of time until the wax containing coating penetrates to a slightdegree the carrier sheet. This, however, requires that the manufacturershall maintain a space to store the goods, and at the same time, have amoney investment tied up in According to this invention a carbon sheetof the second class is obtained which is substantially non-stenci'lling,due to the fact-that the coloring matter penetrates the paper or othercarrier, and which also is non-curling because the coloring coating isso intimately combined with the paper or other carrier sheet that thelatter has substantially a uniform co-eflicient of expansion throughout.y

u The drawing shows in section. a carbon sheet with three clearlydefined layers,.but it must be understood that this is only for thepurpose of illustrating the sequence of final production being ahomogeneous structure in whichno definite layers are present.

.In carrying out this invention, a carrier sheet 1 is employed which hasa low satue rabili but-which preferably has a higher satura ility thanthe carrier sheets usually employed in carbon sheets of this class. A

carrier sheet, which may be employed is made from a pulp composedlargely of linen-mixed with a small percentage 0t precipitate of chalk,so that the pa or produced coating of the different fibers has a slightsaturability.

A 'color coating 2, which may be employed, embodies an insoluble colorsuch as lamp black, a wax, oleic acid and some one or more of the basicaniline oil soluble colors'. The color coating is applied to-thecarrier, preferably one whose saturable properties have been increasedin a manner hereinbefore mentioned, by a coating mas chine which runs ata high rate of speed, the

a common custom. The speed of the coat- [in 'machine may be materiallyincreased in use. Afte the first coating, either on the same machine oron another machine, immediately orafter the coating has been permittedto partially penetrate the carrier sheet, the carbonsheetis. againheated and immediately cooled, thus causing-the wax and oils cf theoriginal coating to still further penetrate the carrier sheet andcarrythe coating therein. -During such reheating a second color coating 3,may be applied. This rerunnin of the carbon sheet either with or withouadditional coatings may be continued any desired number of times untilthe degree of saturation of the carrier sheet desired is obtained. Thesecond or any one or more of the. coating after the first coating maynot contain the soluble colors but may contain an insolu-/ ble color.From the foregoing it will be seen that there has been provided a newmethod .of making carbon paper whereby there is ob-' tained a carbonpaper in which the color coating is substantially homogeneous with thecarrier sheet, so'that the stencilling properties of the sheet arereduced to a minimum, thus increasing the life of the carbon s heet.- Atthe same time, a. sheet is obtained which is non-curling due to the factthat the color coating penetrates the carrier sheet and gives to thesheet, as whole, a substantially equal coefficient of expansion. Thesheet also has a heavier body and this naturally tends to stop thewrinkling and the consequent cracking of the coating. The carbon sheetproduces a larger number of copies, as only a small portion of thecoating is removed by each use. In fact the sheet may be employed untilit is substantially worn out through the use thereof by the typewritingmachine. This is diiierent from the ordinary carbon whereupon the firstuse siibstantially all of the coating is removed from the surface at theprinting point.-

. What I claim as my invention and desire to secure by Letters Patentis:

1. A method of making carbon paper which consists in applying, to aslightly saturable carrier sheet, a heated wax-contain color coatingwith penetrating proper- .tles, immediately" cooling the waxcontamingcolor-coating, and" thereafter reheating the coated sheet andimmediately cooling the same to cause the color-coating to still furtherpenetrate the carrier'sheet.

2. A method of making carbon sheets which consists in applying, to aslightly saturable carrier sheet, a heated wax-contain- .ingcolor-coating with penetrating properties, immediately cooling the-wax-containing color-coating, thereafter applying to the coated sideofsaid sheet'another heated Wax-containing. coating, heating the coatedsheet to cause the first coating to still further penetratethe carriersheet and immediately cooling said sheet.

3. The method of'inaking carbon paper which consists in applyinga heatedwax- --containing color-coating to the sheet, im-

mediately cooling said coating, and thereafter reheating and1mmed1ately" cooling the coatmga number of times to obtain a carbonsheet saturated'by the coating to a desired degree. y 7

4. A method of lmak ingcarbon sheets which consists in providing asaturable carrier. sheet, coatingsaid sheet with a hot wax-containingsoluble color-coating, immediately cooling said coating, and thereafterreheat-ing and immediately cooling the sheetto cause the color-coatingto penetrate the sheet. v

A method of making carbon sheets which consists in providing a saturablecarrier sheet, coating said sheet with a hot waxcontaining solublecolor-coating, immediately coolings aid coating, and thereafter applyingto the coated side. of said sheet a heated insoluble color coating andimmediately cooling said sheet and coating.

6.- A non-curlirig carbon sheet-comprising a carrier sheet, awax-containing soluble color coating penetrating the carrier sheet, anda separate wax-containing insoluble color-coating applied to the firstmentioned coating. 1

wiNriELn P.- PEMBROKE.

